The present invention relates to scarifying machines and more particularly to scarifying machines which carry a plurality of cutters.
A long standing problem in industrial floor maintenance has been the removal of tough and gummy soilages as well as the removal of floor coating materials. Such materials typically include petroleum deposits, food residues, dust and other soil materials, spills, paints and plastic resins. Over the years, many methods have been employed for the removal of such materials. The methods have included the use of heavy duty powered round wire and butcher wire brushes, brushes with abrasive particles embedded in nylon bristles, automatic scrubbing machines which may use multiple soaking passes, open woven metallic sand papers, free abrasive scouring, light aggressive scarifying tools as well as harsh chemical removers that dissolve and suspend materials. The known methods have certain disadvantages. For example, the known methods generally require excessive amounts of power and may damage the surface of the floor. The known methods and equipment generally have high wear thus requiring frequent tool replacement. Also, the known methods generally require specialized machines which are not always available. Moreover, such known methods tend to be slow and inefficient. The chemical removers may require toxic chemicals and generally produce hazardous conditions on the floors due to the wet slippery nature. The known methods typically result in demanding and unpleasant work.
Previous methods for material removal have been of two general types, namely, the wet methods and the dry methods. The wet methods typically require application of highly alkaline or solvent based chemicals to soften, lift or dissolve the material. Illustrative of such solvent based chemicals is a commercially available product sold under the trademark Tennant 509. The chemical solvent is spread over the floor surface and allowed to react for a period of up to about one hour. Handscrapers are used to remove and collect the lifted material in the form of a wet sludge. The sludge is shoveled into drums for remote disposal at a site appropriate for disposal of hazardous materials. This process may be repeated to remove multiple layers of coatings. The surface may then be power sanded or dry abraded with an adrasive bristle brush. The surface is, subsequently, wet scrubbed.
The dry methods are illustrated by use of stiff wire brushes in such machines as the Tennant Models "R" and "K-4". Such equipment may use steel brushes or tools containing rows of hardened metal star-shaped washers to remove difficult soilage buildups and coatings. The dry methods would also include sand blasting or powered sanding techniques. U.S. Pat. No. 2,769,626 (Becker) shows a device for dry removing linoleum asphalt tile. The device has vertical removable flared tubing cutters around its periphery. U.S. Pat. No. 3,687,532 (Boyd) shows a disc device including many thin vertical discs attached around the periphery of the disc. U.S. Pat. No. 3,347,596 (Brejcha) shows a surfacing machine for terrazzo floors including rigidly held but removable cutting elements made of tungsten carbide. The cutting elements have negative axial rake that achieves longer tool life. The cutters cut through a surface contour to level or plane instead of following the surface in preparation for surface smoothing operation.
Illustrative of cylindrical tools used to remove a gummy or softened material from a permanent hard surface are disclosed in U.S. Pat. Nos. 1,616,895, 1,721,266 and 3,061,860. The known methods and tools are expensive and require large power sources, are slow and inefficient in their operation, have generally short lives, tend to clog with removed materials and often permanently scar or damage the floor surface.
The present invention overcomes those problems inherent in previous methods and tools. For example, a person removing material by hand-scraping can cover about 50 square feet per hour; whereas, a machine using the present tool may cover between 2500 and 3000 feet per hour. The present tool has a long life and is non-clogging. The present tool will cut through and scrape off gummy, softened materials and their interface with a permanent surface, such as a concrete floor, without causing damage to the permanent surface. The present tool is low in power consumption, is suitable for scraping off chemically treated, heated or otherwise softened coatings or grime and yet the operator is permitted to work on a safe dry surface. Use of the present tool permits use or selection of chemicals which are non-hazardous or do not result in disposal problems.